Adobe After Effects CS4 - Manual (Page 489)

483 USING AFTER EFFECTS CS4
Effects and animation presets
Last updated 12/21/2009
Elasticity Specifies how closely the image follows the shape defined by the curve. Stiff distorts the least, while Super
Fluid distorts the most. In general, use the stiffest setting possible that doesn’t create polygonal images.
Interpolation Method Specifies a method for the interpolation that Smear performs between keyframes. Linear requires
two or more keyframes and performs a straight-line interpolation between the keyframes. Discrete produces animations
in which the distortions change at keyframes. Smooth requires three or more keyframes and approximates the distortion
using cubic curves, producing distortions with graceful motion. If you need further precision in the animation between
keyframes, add more keyframes. For example, a distortion representing a 90-degree rotation between two keyframes
appears as a folding of the image. To make this distortion more fluid, add a keyframe for every 10°.
Use the Smear effect
1 Open the layer in a Layer panel.
2 Create or paste the masks to use as the boundary mask and the source mask.
3 Position the boundary mask to specify the area of the layer you don’t want Smear to affect.
4 Scale and position the source mask over the area you want to move.
5 Make the Composition panel active, and choose Effect > Distort > Smear.
6 Enter a Percent value to specify the amount of smear applied.
7 In the Composition panel, move the source mask to its destination position by dragging it or by using the Mask
Offset value.
8 Use the Mask Rotation control to rotate the source mask, and use the Mask Scale control to scale it.
9 Drag the Percent slider as needed, and choose a setting for Elasticity.
Spherize effect
The Spherize effect distorts a layer by wrapping a region of the image onto a sphere. The quality setting of the layer
influences the Spherize effect. Best quality samples the displaced pixels to subpixel precision; Draft quality samples to
the nearest whole pixel.
This effect works with 8-bpc and 16-bpc color.
Transform effect
The Transform effect applies two-dimensional geometric transformations to a layer. This effect supplements the
transform properties available for each layer in the Timeline panel. Anchor Point, Position, Rotation, Scale, and
Opacity properties function much the same as the layer transform properties in the Timeline panel.
You can specify the shutter angle for motion blur for this layer independently of the shutter angle for the composition.
(Motion blur must be enabled for the layer and for the composition for this to be relevant.)
Note: This effect is relative to the input layer. Therefore, to make a layer rotate around the upper left corner, open the
layer in the Layer panel, choose Transform from the Layer panel menu, and then move the anchor point and the position
to the upper left corner.
This effect works with 8-bpc and 16-bpc color.
Skew Skew amount.
Skew Axis The axis about which skew occurs.
Aharon Rabinowitz provides a video tutorial on his All Bets Are Off website that shows how to use the Skew properties
of the Transform effect to simulate perspective in the movement of a cloud layer based on a still image.